• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.4
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• pp.313-321
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• 2004

Korean government has offcially decided to adopt global geodetic reference system(ITRF and GRS80) from 2007 keeping pace with the spread of GNSS. Industries related with LBS and telematics have called for use of the new coordinate system suitable for GIS/GPS applications. The government also defined the single plane coordinate system that covers entire korean peninsula as UTM-K considering DB-based framework data and user-friendliness, and its defects were corrected while being applied to the building of road framework data. The TM projection, and origin scale factor of plane coordinate system, 0.9996were employed in order to satisfy the single plane coordinate system for the entire Korean peninsula. For the origin of plane coordinate system, longitude of $127^{\circ}$30'00" and latitude of $38^{\circ}$00'00" were applied and, for the initial value of plane coordinate system, N=2,000.000m and E=1,000,000m were used. In addition to considerable savings in costs, it is expected that the UTM-K is applicable for correcting errors occurred during acquisition of geographic information and for aggregating map data produced by different sources. However, during the initial stage for introduction, confusion is forecasted due to the use of two different coordinate systems, which may be minimized by continued publicity and education.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.1
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• pp.16-23
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• 2000

A topography-precipitation relationship derived from the southern part of Korean Peninsula was applied to North Korea where climate stations are few and widely separated. Two hundred and seventy seven rain gauge stations of South Korea were classified into 8 different groups depending on the slope orientation (aspect) of the region they are located. Monthly precipitation averaged over 10 year period (1986-1995) was regressed to topographical variables of the station locations. A 'trend precipitation' for each gauge station was extracted from the precipitation surface interpolated from the monthly precipitation data of 24 standard stations of the Korea Meteorological Administration and used as a substitute for y-axis intercept of the regression equation. These regression models were applied to the corresponding regions of North Korea, which were identified by slope orientation, to obtain monthly precipitation surface for the aspect regions. 'Trend precipitation' from the 10 year data of 27 North Korean standard stations was also used in the model calculation. Output grids for each aspect region were mosaicked to form the monthly and annual precipitation surface with a 1km$\times$1km resolution for the entire territory of North Korea. Spatially averaged annual precipitation of North Korea was 938 mm with the standard deviation of 246 mm.

• International Journal of Highway Engineering
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• v.14 no.1
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• pp.95-102
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• 2012

This study has been conducted to characterize the relations between the accident rate and the overlap section elements where the horizontal alignment and vertical alignment are overlapped. The researches were performed on Horizontal curve sections of 4-lane highways with 100km/h of design speed and speed limit. Korea Highway Corporation's Geographic Figurative Information System was adopted for geometric organization and Highway Traffic Accident Statistics was used. The results reveal that sections made of a single slope without vertical curve has greater accident rate than those with vertical curve, and that sections with 1 vertical curve are higher in the accident rate than those with over 2 vertical curve. For the sections with 1 vertical curve, SAG sections are higher than CREST sections and for the previous straight section of horizontal curve are higher than curved ones. In particular, when the road surface is wet, the accident rate is closely related with SAG vertical curves or leftward horizontal curved sections. This study will have meanings that it proposes the importance of design of road alignment by taking consideration of 3D synthetic alignment conditions for improvement of the road safety.

• Journal of Korea Water Resources Association
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• v.44 no.3
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• pp.169-177
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• 2011

The impacts of climate change on paddy irrigation water demands in Korea have been analyzed. High-resolution ($27{\times}27\;km$) climate data for the SRES A2 scenario produced by the Korean Meteorological Research Institute (METRI) and the observed baseline climatology dataset were used. The outputs from the ECHO-G GCM model were dynamically downscaled using the MM5 regional model by the METRI. The Geographic information system (GIS) was used to produce maps showing the spatial changes in irrigation water requirements for rice paddies. The results showed that the growing season mean temperature for future scenarios was projected to increase by $1.5^{\circ}C$ (2020s), $3.3^{\circ}C$ (2050s) and $5.3^{\circ}C$ (2080s) as compared with the baseline value (1971~2000). The growing season rainfall for future scenarios was projected to increase by 0.1% (2020s), 4.9% (2050s) and 19.3% (2080s). Assuming cropping area and farming practices remain unchanged, the total volumetric irrigation demand was projected to increase by 2.8% (2020s), 4.9% (2050s) and 4.5% (2080s). These projections are contrary to the previous study that used HadCM3 outputs and projected decreasing irrigation demand. The main reason for this discrepancy is the difference with the projected climate of the GCMs used. The temporal and spatial variations were large and should be considered in the irrigation water resource planning and management in the future.

• Journal of Korea Water Resources Association
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• v.43 no.11
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• pp.995-1009
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• 2010

Accelerated soil erosion due to extreme climate change, such as increased rainfall intensity, and human-induced environmental changes, is a widely recognized problem. Existing soil erosion models are generally based on the gross erosion concept to compute annual upland soil loss in tons per acre per year. However, such models are not suitable for event-based simulations of erosion and deposition in time and space. Recent advances in computer geographic information system (GIS) technologies have allowed hydrologists to develop physically based models, and the trend in erosion prediction is towards process-based models, instead of conceptually lumped models. This study aims to propose an effective and robust distributed rainfall-sediment yield-runoff model consisting of basic element modules: a rainfall-runoff module based on the kinematic wave method for subsurface and surface flow, and a runoff-sediment yield-runoff model based on the unit stream power method. The model was tested on the Cheoncheon catchment, upstream of the Yongdam dam using hydrological data for three extreme flood events due to typhoons. The model provided acceptable simulation results with respect to both discharge and sediment discharge even though the simulated sedigraphs were underestimated, compared to observations. The spatial distribution of erosion and deposition demonstrated that eroded sediment loads were deposited in the cells along the channel network, which have a short overland flow length and a gentle local slope while the erosion rate increased as rainfall became larger. Additionally, spatially heterogeneous rainfall intensity, dependant on Thiessen polygons, led to spatially-distinct erosion and deposition patterns.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.5
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• pp.599-605
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• 2009

Changes of atmospheric pressures cause short- and long-term crustal deformations and thus become error sources in the site positions estimated from space geodesy equipments. In this study, we computed daily displacements due to the atmospheric pressure loading (ATML) at the 14 permanent GPS sites operated by National Geographic Information Institute. And the 10-year GPS data collected at those stations were processed to create a continuous time series of the height estimate. Then, we corrected for the ATML from the GPS height time series to see if the correction changes the site velocity and improves the precision of the time series. While the precision improved by about 4% on average, the velocity change was not significant at all. We also investigated the overall characteristics of the ATML in the southern Korean peninsula by computing the ATML effects at the inland grid points with a $0.5^{\circ}{\times}0.5^{\circ}$ spatial resolution. We found that ATML displacements show annual signals and those signals can be fitted with sinusoidal functions. The amplitudes were in the range of 3-4 mm, and they were higher at higher latitudes and lower at the costal area.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.4
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• pp.259-267
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• 2013

GIS-based web map service is all the more accessible to the public. Among others, location query services are most frequently utilized, which are currently restricted to only one keyword search. Although there increases the demand for the service for querying multiple keywords corresponding to sequential activities(banking, having lunch, watching movie, and other activities) in various locations POI, such service is yet to be provided. The objective of the paper is to develop the k-IPS algorithm for quickly and accurately querying multiple POIs that internet users input and locating the search outcomes on a web map. The algorithm is developed by utilizing hierarchical tree structure of $R^*$-tree indexing technique to produce overlapped geometric regions. By using recursive $R^*$-tree index based spatial join process, the performance of the current spatial join operation was improved. The performance of the algorithm is tested by applying 2, 3, and 4 multiple POIs for spatial query selected from 159 keyword set. About 90% of the test outcomes are produced within 0.1 second. The algorithm proposed in this paper is expected to be utilized for providing a variety of location-based query services, of which demand increases to conveniently support for citizens' daily activities.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.2
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• pp.95-104
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• 2018

This study has the purpose of suggesting the method to analyze the spatiotemporal change of satisfaction concerning the officially assessed land price using geostatistical analysis. Analyzing the spatial distribution characteristic of officially assessed land price using present GIS (Geographic Information System) or is staying at qualitatively suggesting the improvement method of the officially assessed land price system. Grouping the appeal strength based on the official price and opinion price of officially assessed land price, GIS DB (Database) was constructed and the time seriate satisfaction were analyzed and compared through spatial density analysis and spatial autocorrelation analysis. As a result, it was found that the difference between the official price and the applicant's price differed depending on individual land, but most of the respondents requested the increase or the reduction of the average land price, which resulted in a large number of request. Analyzing the satisfaction of the officially assessed land price by using GIS, it was known that satisfaction of officially assessed land price could be analyzed by using the difference of the opinion price and not only the officially assessed land price. Spatiotemporal change of officially assessed land price satisfaction was known to be possible through spatiotemporal pattern analysis method such as spatiotemporal auto-corelation analysis and hotspot analysis etc using GIS. In short, regionally positive or negative significant relationship was investigated through spatiotemporal analysis using annual data.

• Korean Journal of Ecology and Environment
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• v.50 no.3
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• pp.286-294
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• 2017

Development of transportation is rapidly reducing the barriers between countries, but this is causing the easier migration of species than the past. Typically, exotic species are imported for the purpose of food, leather, and pets. However, it has been introduced into the wild through artificially or naturally paths, and recently they are become a main cause of ecosystem disturbance. In this study, we investigated exotic turtle species introduced into the wild and analyzed their distribution characteristics. As a result of filed surveys, totally 4 genus 8 species 62 individuals of exotic turtles were found from 126 reservoirs in Gangwon-do and Gyeongsangnam-do, South Korea. In particular, Trachemys scripta elegans showed relatively high frequency than other turtle species and the natural reproduction of T. s. elegans was confirmed in some areas. On the other hand, the frequency of discovery of exotic turtles except T. s. elegans was relatively low, and the range of the areas was limited. Especially, exotic turtles except T. s. elegans were mainly found in public places such as reservoirs in the park. As a result of analyzing the distribution characteristics of exotic turtles using geographic information system, the turtles' distribution showed a high correlation with the artificial factor such as "urban". In this study, we identified the distribution characteristics of exotic turtles in the Korean wild, and these results will be important data for understanding status the and establishing effective management methods for exotic species.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.3
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• pp.241-247
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• 2012

The national geodetic reference frame of Korea switched to the International Terrestrial Reference Frame (ITRF) in 2003. In order to study the land area changes, we calculated the entire land area of Korea using the administrative boundaries of census data provided by Statistics Korea. The standard transformation procedure by the National Geographic Information Institute (NGII) was followed. The Transverse Mercator (TM) projected coordinates were transformed into the GRS80-based world geodetic reference frame, and the ellipsoidal and the projected areas were calculated. The provinces that range over two projection origins were divided into two polygons and projected using appropriate origins. After the transformation, all boundaries were shifted in the northwestern direction, resulting in a decreased area of $1.36km^2$ (about 0.0013%) on the projected plane. Moving the boundaries into a high latitude area cancels out the effect of the enlarged ellipsoid. In addition, the rate of change shows that a higher-latitude province is more sensitive to the shift of the boundaries. The data by Statistics Korea is significantly different from those of the Ministry of Land, Transport and Maritime Affairs (MLTM), thus it is urgently recommended that the data are integrated and unified.